420A smoking (can't figure out why!)

[lxRAMMSTEINxl]

Hey fellas. Hopefully someone can shed some insight to this issue. A few months back my friends noticed my car was barely smoking at an idle. But couldn't see it smoking when driving.

I didn't put to much concern into it. When the time comes it needs fixed, I'll fix it.

About 2 weeks later, my brand new catalytic converter blew up. The insides came apart and were plugging my exhaust. I removed the cat, punched everything out of the inside, and put the cat back on. My car doesn't have a muffler so it's technically "straight piped" now.

About 2 weeks after that I noticed the smoking was getting worse at an idle, and when stopping at a red light I can see the smoke when I look out my window. It smells like really bad exhaust leak and is almost transparent. It's not dark enough to tell what color it really is but doesn't smell like oil.

I compression checked all cylinders. They all came up 210psi. Plugs look great, no signs of oil. I replaced my plugs and wires and still smoking. Don't notice antifreeze loss or oil loss, or fuel consumption from too much gas. The car runs great. No check engine light. I've cleaned my intake and throttle body, still no help.

Anyone got any ideas?

Edit: it is a 420A w/ 5 speed.

 

[Dsmkauai]

Rear o2 is bad. It probably got fried when the cat blew

 

[lxRAMMSTEINxl]

I'm still kind of skeptical...I've been told numerous times now that sensor 2 doesn't effect air/fuel ratio.

 

[lxRAMMSTEINxl]

Will getting a new rear O2 sensor fix this issue - even though I have no cat?

 

[Dsmkauai]

It's there to test the efficieny of the cat and may have little effect on fuel trims. Since you don't have a cat the ecu is thinking that it's not being efficient. And probably making adjustment to reflect that. Which it really doesn't need to do. That's why you need a way to trick it to look like it's working properly.

 

[lxRAMMSTEINxl]

So without a cat on the car, there's no way to fix this smoking issue?

 

[Dsmkauai]

It's hard to say bro if it's a rich smoke because of the o2 it's possible it may fix it. They make a devise to put the o2 in when you have no cat to trick the ecu. You might wanna look into that along with a new o2 sensor. It's possible just replacing the o2 fill fix it and clear up your issue. Something like this http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html?gclid=CIGjw_Wzmc0CFU1gfgodC6IF9A. If you can see what color the smoke is let use know.

 

[JaysGSX]

The car will run fine without a rear O2 sensor. The front O2 is what handles fuel mapping, and the rear is simply to let you know if your cat is functioning. I have no rear O2, or cat and my wide band reads a steady 14.3 to 14.7. You will get a CEL for the rear O2, that's about it. If you were running really rich, you would be able to see color in the smoke coming out of the exhaust since it would be quite dark. Sounds like valve seals to me.